Sept. 23, 1886] 
NATURE 
513 
the managers of the local newspaper press in New Zealand 
very full and graphic accounts of the volcanic outburst of June 10 
have already reached this country, and have been copied into the 
English papers. On the day of the eruption, Dr. James Hector, 
C.M.G., F.R.S., the Director of the Geological Survey of New 
Zealand, started for the locality, and his preliminary report, 
accompanied by maps and plans, has been published. Dr. 
Hector concludes that the eruption was a purely hydrothermal 
phenomenon on a gigantic scale, and that it was unaccompanied 
by any ejection of freshly molten lava either in the form of 
fragmental matter or of lava-streams. I have been favoured by 
Mr. J. E. Clark, F.G.S., with specimens of the material ejected 
during the eruption, and the microscopic examination of these 
entirely supports Dr. Hector’s conclusions. It is a most un- 
fortunate circumstance that the beautiful sinter-terraces of 
Rotomahana appear either to be blown to fragments or covered 
up under the enormous masses of mud thrown out in that 
locality. It luckily happens that a number of most excellent 
photographs, which illustrate very beautifully the characters of 
the wonderful sinter-formations, have been obtained. Mr. Josiah 
Martin, F.G.S., has especially devoted himself to the study of 
the district, and the series of photographs now exhibited con- 
stitute an invaluable record of the characters of the district 
destroyed by the eruption. These photographs show the points 
at which the volcanic cones were formed upon Tarawera, and 
the beautiful characters of the White Terrace (Te Terata), and 
of the Pink Terrace (Otukapuarangi), and the other wonders 
which surround the now destroyed Lake of Rotomahana. Now 
that the European settlement has been formed at Rotorua, a 
great service would be rendered to science if a meteorological 
station could be established there, and by simultaneous observa- 
tions of the atmospheric conditions, and of the state of activity 
of the numerous hot springs, the question of the exact relations 
between these two sets of phenomena clearly established. When 
we remember that a fall of r inch in the barometer is equivalent 
to the removal of a load of nearly 90,000 tons over every square 
mile of surface, the effect produced on a district where steam 
issues whenever a walking-stick is thrust into the ground must 
be enormous. What is especially needed, however, by vulcano- 
logists is a carefully tabulated series of records in the place of 
the general statements which have hitherto been published on 
this most important question. 
The Relations of the Middle and Lower Devonian in West 
Somerset, by W. A. E. Ussher, F.G.S.—It has been suggested 
by Mr. Champernowne that the Foreland and Hangman grits 
might really be the same series, the appearance of conformable 
superposition of Lynton upon Foreland beds at Oare being 
ascribed to inversion. According to this view the downthrow 
of the fault at Oare would be to the north. The paper dis- 
cusses this suggestion, its important bearing on the mapping of 
the area entitling it to consideration. The author advances five 
points in favour of the hypothesis, and three adverse to it, and 
gives some reasons why such difficulties as are experienced in 
drawing boundaries between the Foreland grits and Hangman 
beds might reasonably be expected to occur. The arguments 
against the identity of the Foreland and Hangman groups are 
too strong to be entertained without positive evidence in its 
favour. The author then briefly disposes of the possibility of 
the absence of the Lynton beds east of Luccot Hill being due to 
unconformable overlap of Hangman upon Foreland rocks, point- 
ing out that if such were the case conglomerates ought to be 
found in the Hangman series, and the junction should also be 
marked by discordant relations of dip and strike. 
A Scrobicularia Bed, containing Human Bones, at Newton- 
Abbot, Devonshire, by W. Pengelly, F.R.S., F.G.S., &c.— 
Description of a bed of fine sandy mud, to feet thick, crowded 
with Scrodicularia piperata, recently discovered near the head 
of the tidal estuary of the River Teign, Devonshire. Its top is 
1 foot above the level of the highest spring tides in the estuary, 
and its bottom 3 feet above the low-water level. Ten feet down 
in the bed were found the following human bones: a skull, part 
of the left superior maxilla, containing two teeth, a right femur, 
and a right scapula—all believed to be of the age of the deposi- 
tion of that part of the bed in which they lay. From the 
presence of the Scvodicularia there is apparently no doubt that 
since the era of deposition the district has been upheaved not 
less than 14 feet, nor more than 27 feet, and that the time was 
in all probability that of the elevation of the raised beach of 
Hope’s Nose, about seven miles south-east of the Scrodécularia 
bed. 
Ona Deep Boring for Water in the New Red Marls (Keuper 
Marls) near Birmingham, by W. Jerome Harrison, F.G.S.— 
Around Birmingham the Keuper sandstone is divided from the 
Keuper marls by a line of fault running from north-east to south- 
west, roughly along the line of the River Rea. West of this 
fault the Keuper sandstone occupies the surface, and yields an 
enormous and unfailing supply of pure water, the Birming- 
ham Corporation alone pumping about eight million gallons 
daily from three deep wells in this formation. East of the line 
of fault the Keuper red marls form an undulating band from five 
to twelve miles in width, the towns and villages on which 
depend wholly on surface waters, or shallow wells in surface 
gravels, for their water-supply. As the Keuper sandstone un- 
doubtedly underlies the Keuper marls throughout the whole or 
the greater part of this tract of East Warwickshire, it is not sur- 
prising that attempts have recently been made to reach its 
locked-up waters by means of deep borings. Some seven or 
eight years ago the Birmingham Corporation bored in Small- 
heath Park (the southern suburb of Birmingham) to a depth of 
440 feet, entirely in Keuper marls. The object of this paper is 
to describe a boring made during the present year at King’s 
Heath, three miles south of Birmingham, at the brewery of 
Messrs. Bates, in search of water, which is now 667 feet deep, 
and still in marls and shales. From comparisons with the 
Keuper marls of Staffordshire, &c., the thickness of the Keuper 
marls at King’s Heath can hardly be more than 700 feet. It is 
to be hoped that the Keuper sandstone will be reached almost 
immediately, and that its water-bearing properties will be such 
as to satisfy the requirements of the district. 
On an Accurate and Rapid Method of Estimating the Silica 
in an Igneous Rock, by J. H. Player, ¥.G.S., F.C.S.—This 
paper describes a method of estimating the silica in igneous 
rocks by (1) fusing the finely ground rock with a flux prepared 
by mixing carbonates of potash and soda and nitrate of potash ; 
(2) disintegrating the glass so obtained by the action of strong 
nitric acid ; (3) driving off nitric acid at a temperature just 
below 250°, thus rendering all silica insoluble ; (4) treating with 
hydrochloric acid, to leave the silica with some impurity, for 
weighing after calcination; (5) separating the impurity by 
means of ammonium fluoride and weighing it. 
Notes on some Sections in the Arenig Series of North Wales 
and the Lake District, by Prof. T. McKenny Hughes, M.A., 
F.G.S.—In this paper the author describes a number of sections 
which cross the Arenig series in different parts of England and 
Wales, and endeavours to explain some apparent discrepancies 
in what is generally a remarkably constant set of beds. He 
starts with the Portmadoc section, where he considers that the 
chief differences of opinion have arisen from mistakes in the 
explanation of the geological structure of the district, especially 
from the wrong identification of some grit bands on opposite 
sides of important faults. | Following the series to the north he 
shows that, although they vary in thickness, the principal zones 
are still represented near Carnarvon ; and, discussing the ques- 
tion of the unconformity of these beds on the Lower Cambrian, 
he points out that the Lower Cambrian rocks are seen to vary 
so much both in character and thickness within short distances 
in the neighbourhood of the existing outcrop of the Archean 
that any argument founded upon their thinning-out or their dif- 
ferent texture must be received with distrust in an area where 
they are known to have been deposited on the flanks of moun- 
tain-ranges of pre-Cambrian age. He then describes some 
localities in the Lake district where the occurrence of the same 
zones has been determined, and points out the difficulty of 
getting rid of such great thicknesses of deposits of fine mud as 
would be implied in the usual interpretation of those areas. 
On the Rocky Mountains, with Special Reference to that part 
of the Range between the 49th Parallel and Head-waters of the 
Red Deer River, by George M. Dawson, D.S., F.G.S., &c., 
Assistant Director, Geological Survey of Canada.—The term 
“Rocky Mountains” is frequently applied in a loose way to the 
whole mountainous belt which borders the west side of the 
North American continent. This mountainous belt is, how- 
ever, preferably called the Cordillera region, and includes a 
great number of mountain systems or ranges, which on the goth 
parallel have a breadth of not less than 700 miles. Nearly 
coincident with the goth parallel, however, a change in the 
general character of the Cordillera region occurs. It becomes 
comparatively strict and narrow, and runs to the 56th parallel or 
beyond with an average width of about 400 miles only. This 
portion of the western 1nountain region comprises the greater 
